The document summarizes events at the end of World War II and the beginning of the Cold War. It discusses how tensions between the US and Soviet Union led to the Iron Curtain dividing Europe. It also describes the US policy of containment to resist Soviet expansion, the Truman Doctrine to provide aid to Greece and Turkey, and the Marshall Plan to rebuild Western Europe's economies. Finally, it summarizes the crisis in Berlin where the Soviets blocked land access to the city, requiring the Berlin Airlift to supply it by air until the blockade ended in 1949.